High sound levels are known to have adverse effects including uncontrolled high and low frequency sound being a threat to health and well-being. The design of a sound absorbing material, suitable for a particular application, is based on a range of frequencies of unwanted sound, which is to be absorbed or damped.
Sound absorption is generally enhanced by increasing the mass of sound absorbers. However, using massive sound absorbers, leads to an increase in either weight or thickness of the sound absorbers, which would not be operable in many places that have space or weight restrictions. Hence, thin and light sound absorbers are desired in many circumstances.
In the world of acoustics, low frequency sounds are difficult to control due to their long wavelengths. Also, with sufficient power, low frequency sounds will pass through just about anything. Accordingly, since the absorption of lower frequency sounds is problematic, there is a need in the art to provide a sound absorbing structure to absorb low frequencies as well as high frequencies, while maintaining a minimum thickness and weight for the sound absorbing structure.